The present invention relates generally to a test device for the brake equipment of a railroad car and more specifically to a portable single car test device for a rail car brake system.
The Association of American Railroads (AAR) has established standard S-486 for testing railroad car brake systems for a single stand alone car. The Standard has two sections, namely, Section 3 for Procedures For Repair Track Test For Air Brake Equipment and Section 4 for Test-Standards Single Capacity Freight Brake Equipment.
In FIG. 1 of the Standard three single car test device with flow meters are illustrated. These devices connect to the glad hand at one end of the car which is connected to the brake pipe. The other end is connected to a source of pressure. The device is a manual device with the operator performing various tests and making readings from the meters. More recently, computerized automatic single car test devices have been designed. One such device is illustrated in U.S. Pat. No. 5,509,727. The test device is connected to four ports provided in the control valve. Various tests are performed automatically. The same pneumatic structure is used with meters as illustrated in U.S. Pat. No. 5,695,258. An electronic brake control valve tester for rail cars and trains is illustrated in U.S. Pat. No. 5,808,909. This is a computerized base tester. A tester is disclosed as connected to the brake control valve at special ports, as in the previous patents or at the glad hand.
The recent revisions to the Standards S-486 provides for testing where brake cylinder measurement taps are provided. New Rule 88 is provided which requires brake cylinder leakage test as outlined in AAR Standard S-401.
The present invention is a portable single car device for a railroad car braking system. The test device has a source port to be connected to a source of pressurized air and a brake pipe port to be connected to a brake pipe connector or glad hand. Valves are provided to selectively interconnect the ports to each other and atmosphere to perform the test. A sensor is provided to determine the pressure at least at the brake pipe port. A controller is connected to the valves and sensor and is programmed to perform the plurality of component test which forms a single car test. A housing includes a hanger configured to mount the housing to the car adjacent to the brake pipe connector. The hanger is configured to mount the housing to the car coupler or to a ladder adjacent to one end of the car.
Preferably, the single car tester is provided in housing having first and second portions connected to each other. In one embodiment, the first portion of the housing includes the controller and the second portion of the housing includes the ports, the valves and the sensors. In a second embodiment, the second portion includes the controller also. The hangar is connected to the second portion.
The first and second portions of the housing are connected by a hinge and have a use and a stored position. The tester includes an operator input device and display which are accessible when the housing is in its use position and unaccessible in the stored position.
The test device has a weight of approximately 50 pounds or less. A first hose of the first length connects the brake pipe port to the brake pipe and a second hose of a second length substantially greater than the first length, connects the brake cylinder port to the brake cylinder test port.
A brake cylinder port is also provided in the second portion of the housing to be connected to a test port or tap of the brake cylinder. The sensor also determines the pressure of the brake cylinder port. A separate sensor or a common sensor may be used to determine the flow rate between the source and the brake pipe ports. A sensor is provided to sense the pressure at the source port and may be a pressure switch.
A portable single car test device for a railroad car brake system includes a source port, a brake port and valves selectively interconnecting the ports to each other and the atmosphere to perform tests. A sensor determines the pressure at least at the brake pipe is provided. A display and an operator input device is also provided. A controller includes a program for performing a plurality of component tests which form a single car test as a function of inputs from the operator in response to displayed information.
The program requests whether the operator wants to continue the last car test. If the input is xe2x80x9cnoxe2x80x9d, the program performs the component tests. If the answer is xe2x80x9cyesxe2x80x9d, the program determines at what point the last car test is stopped and restarts the component tests as a function of the stop point. The program restarts at one or more of the following tests: brake pipe leakage test, system leakage test, emergency test, and accelerated application valve test. The program can also restart at one or more the following starting procedures: preliminary procedures and inspections, and connecting test device to the car.
The program requests identification of the components in the system. This includes one or more of the following:
type of control valve;
is an empty load device present;
is the brake cylinder body or truck mounted;
is a brake cylinder pressure tap present;
is a slack adjuster present;
is an A-1 reduction valve, separate vent valve or separate emergency portion present; and
the length of the car.
The program requests confirmation that a plurality of the preliminary procedures and inspections have been completed. The program prompts the operator, through the display, for each of the preliminary procedures and inspections. The preliminary procedures include chocking the wheels, releasing the hand brake, closing the dirt collector and cut-off cock, and draining the reservoirs.
The program includes a prompt with suggested corrective action for a failed component test. Upon receipt of the stop command, the program resets the brake system. Upon receipt of the start command, the program begins the component test again.
The program includes a brake pipe leakage test. This test includes operator confirmation that the angle cocks on the brake pipe are open, connecting the source port to the brake pipe port and operator confirmation that air is blowing out of the open brake pipe connector. The brake pipe leakage also includes operator confirmation of attachment of a dummy coupling to the brake pipe connector and that the retainer is set in direct release position. The program then measures the flow rate between the source and the brake pipe ports.
The program includes a separate venting device test including performing a continuous quick service test if an A-1 reduction relay or a separate emergency portion is in the brake system.
The program performs a service stability and emergency sensitivity test if a separate vent valve or an emergency portion is in the brake system. The program also includes a system leakage test and a plurality of component tests are performed subsequent to the system leakage test. After repair or replacement of the failed component, the program restarts with the system leakage test.
The system leakage test includes connecting the source port to the brake port and taking a series of brake pipe pressure measurements at a fixed interval. The leakage test takes only two measurements if the two measurements are substantially equal. The program determines if the difference between two measurement is greater or less than a first value. If greater, it continues taking measurements for no greater than a first number of pairs of measurements. If less, the program continues taking measurements for no greater than a second number of pairs of measurements. The second number of measurements is greater than the first number.
The program includes a control valve service stability test following the system leakage test. The control valve service stability test includes connecting the brake pipe port to exhaust to produce a first reduction of brake pipe pressure and measuring the brake pipe pressure after the reduction. The program then determines if the brake pipe pressure is reducing after reduction. If reducing, the program connects the source port to the brake pipe port to produce a fixed increase of brake pipe pressure which is less than the reduction. Next, the program determines if the brake pipe pressure is still reducing.
The program includes a brake cylinder leakage test following the service stability test. The brake cylinder leakage test includes connecting the brake pipe port to exhaust to produce a further reduction of the brake pipe port pressure. The program then measures the brake cylinder pressure before and after the further reduction. The difference between the measured brake cylinder pressure is compared to a first value for an empty car and to a second value for a loaded car. For an empty car which has passed the leakage test, the operator is prompted through the display to block an empty/load device in a load position. The program then connects the source port to the brake pipe port to recharge the brake pipe. The brake cylinder leakage test for the loaded car is then repeated. The brake leakage test may be performed independent of the service stability test.
The program includes an emergency test including a service sensitivity test and an emergency application test. The emergency application test measures the brake pipe pressure of a brake pipe system that does not have a brake cylinder tap and measures the brake cylinder pressure if the brake system has a brake cylinder tap.
The program includes a brake application test and a retainer valve test performed after the brake application test. The retainer valve test includes measuring brake cylinder pressure if the brake system has a brake cylinder tap. If the brake system does not have a brake cylinder tap, the program prompts the operator to move the retainer valve from a high pressure position to a direct exhaust position and report if strong air is blowing from the retainer valve.
The program also includes a brake application test and a manual release of valve test performed after the brake application test. The manual release valve test includes measuring the brake cylinder pressure if the brake system has a brake cylinder tap and includes prompting the operator to report if the brakes had released.
A method of charging a railroad car brake system through a brake cylinder tap includes connecting a source of pressurized air to the brake cylinder tap. Then, alternately connecting the brake pipe connector to the source and the atmosphere to charge the reservoir through the brake cylinder. The brake pipe is connected to the source for a sufficient time to charge a quick action chamber of the control vale and is connected to the atmosphere for a sufficient time to cause the control valve to open a first valve in the control valve which connects the reservoir to the brake cylinder. The source is then reconnected to the brake pipe after the first valve has closed.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.